Part of the CA SymDump for CICS installation is to define a SYSMDUMP DD statement and add it to the CICS startup JCL.
If CA SymDump for CICS abends during dump capture time an SVC dump is created for the abend and is used for diagnostic purposes.
Step 17 Adjust the CICS JCL and Startup parameters of the Symdump CICS r 8.5 install guide states
Add the following statement to identify a dump location should CA SymDump for CICS abend while capturing a transaction dump:
//SYSMDUMP DD DSN=your.dataset.name,
Pre-allocate your data set with RECFM=FB,LRECL=4160,BLKSIZE=4160 and with enough space to capture an SVC dump for your CICS region.
Some installations would like to avoid the overhead associated with producing a SYSMDUMP especially in the production environment.
Is an option available to turn the SYSMDUMP creation off without removing the SYSMDUMP from the CICS startup JCL?
Starting with release 8.5 at the P1005 cumulative maintenance level a new IN25OPTS options parameter SYMDSVCD is now available.
The default for the SYMDSVCD option is YES. If you set SYMDSVCD to NO the SVC diagnostic dump will not be produced if CA Symdump for CICS abends at dump capture time. See the r 8.5 Installation Guide Chapter 5 Modifying Options for instructions on changing the CA SymDump for CICS IN25OPTS options.